Metalworking device



' June 20, 1944. v. E. ROBBINS METALWORKING DEVICE Filed Sept. 2, 1939 VERA/0N E, #055010 IIVVE/VTQR ATTORNEY Patented June 20, 1944 UNITED STATES PATENT 1 OFFICE lfETllawimnmci Vernon E. Bobbins, Berkeley,

Application September a, 19:9. Serial No. 293,23:

a cum. (on. 81-15) The present invention relates to a metal working device of the class particularly adapted for restoring curved metal surfaces such as automobile fenders and the like to their original conareas fiied,-rendering complete fracture upon a subsequent impact much more likely.

Various metal working devices superficially similar to that of the present invention have been proposed for the purpose of avoiding the foregoing difliculties, but so far as I am aware, all have employed elements comparable in their effect to the hammers previously employed, and incapable of restoring a curved sheet metal surface accurately to its original contours without weakening or stressing the metal.

The principal object of the present invention is to restore deformed metal surfaces to their original contours without weakening or stretching the metal. 7

A further and more specific object of the informity from-an opposite direction to that illustrated in Figure 1:

Figure 5 is a detail, means: and

Figure 6 is a detail view in section of the pivotally mounted element l8 and track is shown in Figure 4; the section being taken on the line H of Figure 4.

Figure 7 is a fragmentary elevational view of a detailed modification.

The device, of the present invention attains the foregoing objects by providing a rockably mounted anvil having a substantially fiat face supported for tangential contact with a roller so that the sheet metal surface to be restored may be engaged at opposite points by the anvil and of an alternate adjustin roller respectively: the support for the anvil and" roller being such as to permit relative movement of the latter elements, the roller moving along the fiat face of the anvil. I

This arrangement is such that an "ironing" of the deformedsheet metal between the roller and vention is to provide a convenient portable device by means of which such operations may be carried out, and generally to improve devices of the same general class to which that of the present invention belongs.

The novel features characterizing a device em-, bodying the present invention are set forth with particularity in the appended claims. The invention itself, however, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments thereof, when read with reference to the accompanying drawing, in which:

Figure 1 is a side elevation, partially in section showing an apparatus for practicing the invention, and illustrating an initial-step of a method of the invention;

Figure 2 is an enlarged fragmentary elevation from the left of Figure 1, the work being'shown in section;

Figure 3 is an elevational view of the apparatus of Figure 1 illustrating a second step in the practice of the invention;

Figure 4 is a fragmentary view of a varied,

form of the apparatus of Figure 1, and also illustrating the method of attack of both modifications when the mechanism is presented to the de- As illustrated in the drawing the apparatus employed comprises a tubular metallic member I treated in such manner as to have an intermediate curved portion 2 of a springy character while the remainder of memberi, including the remaining curved portions, is relatively rigid and inflexible. The end portion 3 of the tubular member I is provided with a recess in which is received the cylindrical stem la of a roller holder 4 in which is rotatably mounted, as shown in Figure 2, a hardened metal, roller 5. Roller holder 4 is adjustable by rotational movement of stem la in its recess and is held in properly ad- .iusted position, with the axis of roller 5 parallel to the axis of pivotal movement of anvil I, by a releasable set screw 6. Roller 5 is somewhat barrel shaped but the mid-portion thereof is preferably cylindrical and preferably 50 about one third of its length.

Pivotaily secured to the other end portion 6 of member I, by means such as pivot pin la, is an anvil I having a substantially perfectly flat surface juxtaposed in adjustable spacial relation to the roller and pivotal about an axis parallel to that of the roller.

In operative relation the anvil and roller are:

placing them in position. To this end the anvil is mounted on a removable member 8 which is slipped into the slots 9 and ill of holders II and H. Member 8 also constitutes an adjustable support for the anvil in that ittakes the form of a lever fulcrumed on the fulcrum l3 of member I! and adjustable therearound as by means of an 7 adjustable screw bearing thereagainst through the member II, or adjustable: by a self locking eccentric to, the areas of fiat sides ii of which are unsymmetrically disposed on either side of a normal radial plane, so that the areas progress inwardly. A suitable lever ll serves to operate the latter described adjustment means.

A modified form of the anvil employed in the device of the present invention is illustrated in Figures 4 and 6 as comprisinga body portion it pivotally mounted on member 8 at 38a and provided with peripheral flanges 26 serving as guides and retaining means for an endless metal band 2i encircling the body portion i8 between said flanges and slidable around the body'portion in the direction of movement of the latter in operation. In order to facilitate such sliding movement the maintenance of proper lubrication between the band 2! and the body member 58, by

t and anvil 1, respectively, when a deformity extending below or above the normal plane of the work is encountered by one or the other. Thus, when the device as a whole is moved in the direction of the arrow A in Figure l, and the roller 4 encounters a deformity such as that indicated at 23, the entire device acts as a lever of the second class having its fulcrum at the point of the work nearest the anvil pivot la, a power arm of the length of the diameter of the C- shaped yolk I and a work arm of the length of the offset of the roller pivotfrom pivot 1a. The ratio of the power arm to the work arm being large, the force exerted in restoring the deformity to its normal plane is many times that exerted by the operator. The same type of operation takes place when a deformity extending above the normal plane of the work is encountered by the anvil 1, except that under such conditions the device functions as a lever of the first class, having its fulcrum at the point of the work nearest the roller pivot, a power arm of the diameter of the yolk, and a work arm of the length of the offset of pivot m from the roller pivot.

In order to effect a smooth application of force to the deformities to be removed, it is desirable to make the yolk l, or a substantial portion thereof, resilient, so that when a deformity is encountered by either the roller 4 or anvil I, the yolk I may be stressed. Such stressing increases the offset of the roller and anvil axes but applies a resilient pressure tending to simultaneously restore them to their original offset relationship andto effect relative movement of the roller and anvil which irons the deformity between these members without applying excessive force which might rupture the metal or strain it beyond its limit of elasticity.

The operation of the device therefore involves no particular skill on the part of the operator, requiring only that hereciprocate the device as indicated by the arrow A in Figure 2 over such deformities as it is desired to remove. The construction of the device is such that, during such reciprocation, the above described actions take place automatically.

As the deformity becomes smaller, the clearance between anvil and roller may be decreased gradually by the adjustment H or by a single step, depending in some degree upon the thickness of the metal and the character of the deformity, and ultimately the adjustment is such that the spring portion of member l-is stressed as illustrated in Figure 3 so that the roller and anvil are actually in compression against opposed surfaces of the metal and in which relation the finishing of the metal to substantially perfect smoothness and in substantially exact restored condition is effected.

By means of the construction in Figure 4 the additional result is accomplished of preventing any sliding of the work with reference to the tractor tape 2!, thus reducing the' resistance to restorative forces and protecting the metal surface against scraping action.

Having described the invention and explained the principle of its operation both in the method and in preferred embodiments of apparatus for carrying out that method in accordance with the statute, it will be apparent that other variations of the invention may be resorted to by those skilled in the art for the purpose of accomplishing one or more of the useful results flowing therefrom without departing from the spirit of the invention. It is therefore to be understood that the disclosed embodiments are illustrative only and the following claims are referred to for a definition of that for which the inventor is secured protection hereby.

In the construction of Figure '7 the anvil 1 is shown to be suspended and pivoted to the free end of a pltman 25 pivotally secured to the arm 8 and limited for movement around pivot 26 by a pair of stops 21. This construction permits the yoke I to be held up or down irrespective of the direction of attack A, as in Figure 1 or as in Figure 4, since the centerline of thrust may be shifted forwardly or backwardly of the roller in preparing for the first step above outlined.

- I claim:

1. A metal working tool comprising a yoke member having a roller mounted on one terminus thereof, an anvil, means for removably securing member having termini, a roller mounted on one terminus, an anvil mounted on the other terminus, said anvil comprising a body portion forming a flat area and providinggatrackway over said area, and a flexible flat member supported against said flat area in sliding engagement therewith'and extending between said flat area of said roller.

3. A device as set forth in claim 2,said flat member being an endless flatband lying in said trackway, said'trackway extending around said body.

4. A metal working tool comprising a yokelike member having termini, a roller mounted on one terminus, an anvil mounted on the other said anvil comprising a body portion forming a fiat area and providing a trackway over said area, and a flat member supported against said flat area in sliding engagement therewith, said fiat member being an endless flat band lying in said trackway, said trackway extending around said body.

5. In a device of the character described, a yoke member having termini, a roller member trunnioned on one terminus and disposed toward the other terminus, means providing a slot disposed toward said roller and endwise of said other terminus secured to said other terminus, means providing an anchor fulcrum on said yoke member and a slot aligned with said first slot, a lever member disposed through said slots and fulcrumed on said anchor fulcrum, means for adiustably positioning said lever member with 5 justing means comprising an adjusting screw and said screw being disposed in said first slot.

7. A device as set forth in claim 5, said adjusting means comprising a flat sided cam.

8. A device as set forth in claim 5, said adjustio ing means comprising an adjusting screw, and

said anvil member being connected to said lever by a link pivoted to both.

9. A device as set forth in claim 5, said adjusting means comprising a flat sided cam member is adapted to lock against said lever, and said anvil having an endless band therearound.

VERNON E. ROBBINS. 

